Utilization of potential of three selected agricultural residues for briquetting as biomass fuels

In this work, investigations were carried out on densification characteristics of briquettes produced from corncob; melon shell and cassava peel residues with a view to finding out which of them would make the best biomass fuels. Ultimate and proximate analyses were carried out to determine the average composition of their constituents. A simple prototype briquetting machine was fabricated to facilitate compaction of these residues into briquettes. Thereafter, densification and fuel characteristics of produced briquettes such as initial, maximum and relaxed densities were determined. Also determined were density, compaction and relaxation ratios. The energy values and compressive strengths of briquettes from the three specimens were also evaluated. The mean moisture contents of corncob, melon shell and cassava peel were 9.47%, 9.60% and 10.76% respectively, while the moisture contents of briquettes were 7.48%, 7.45% and 8.78% respectively. The initial, maximum and relaxed densities were 155, 650, and 325kg/m3 respectively for briquettes produced from corncob, while the corresponding values for briquettes produced from melon shell and cassava peel were 142.87, 561, 286.42kg/m3; 251.50, 741.13, 386.40kg/m3 respectively. The relaxation ratios of 1.69, 1.95 and 1.92% were obtained for briquettes produced from corncob; melon shell and cassava peel respectively. The heating value calculated for briquettes from corncob, melon shell and cassava peel were 20,890, 21,887 and 12,765kJ/kg respectively, while the corresponding values of compressive strengths were 2.34, 2.30 and 1.53kN/m2.